The present invention relates to an automatic tool replacement system for automatically replacing tools such as dies and punches used in a multi-stage press forming machine, which press-works material step by step to continuously form products or parts of various shapes with an array of plural dies and punches disposed against each other.
A multi-stage press forming machine includes a multi-stage press station equipped with plural dies disposed at preset locations on a base thereof and the same number of punches each opposed to the corresponding die and mounted on the front face of a ram pushed forward and backward against the dies. A material bar supplied from the back of the base is cut in given lengths by a bar cutter mounted on an end of the base, and successively fed into each stage of the press station by a material transfer unit. The cut pieces are press-worked at the multi-stage press station step by step and continuously formed into a final product with a given shape. Such multi-stage press forming machines can make various products of different shapes by replacing its dies and punches. Various tool replacement apparatus and systems have been proposed for quicker, more efficient replacement of dies and punches and thereby for improving the production efficiency.
When products of a different shape are to be manufactured, the bar cutter for cutting a material bar in given lengths and the material transfer unit for feeding the cut pieces to the multi-stage press station need to be replaced as well as dies and punches, since different products require material bars of different size and quality. Although dies and punches are relatively readily replaced with a conventional replacement system, replacement of the bar cutting mechanism and the material transfer unit requires both time and labor. Thus a total replacement system with a high replacing efficiency has been demanded.